Luminaire



p 1965 w. NlEDER-WESTERMANN ETAL 3,209,140

LUMINAIRE 5 She ecs-Sheet 2 Original Filed Jan. 27. 1960 P 23, 1965 w.NlEDER-WESTERMANN ETAL 3,209,140

5 Sheets-Sheet 3 Original Filed Jan. 27, 1960 Sept. 28, 1965 W.NlEDER-WESTERMANN ETAL LUMINAIRE 5 Sheets-Sheet 4 Original Filed Jan.27, 1960 Fig.8.

Unitcd States Patent 3,209,140 LUMINAIRE Winfried Nieder-Westermann,Parma, Edmund L. Izzi,

North Olmsted, and John Moro, Cleveland, Ohio, as-

signors to Westinghouse Electric Corporation, Pittsburgh, 'Pa., acorporation of Pennsylvania Continuation of application Ser. No. 5,064,Jan. 27, 1960.

This application Jan. 14, 1963, Ser. No. 251,441 5 Claims. (Cl.24051.'11)

This application is a continuation of copending application Serial No.5,064, now abandoned, entitled Luminaire, filed January 27, 1960, by W.Nieder-Westermann, E. L. Izzi and J. Moro, and assigned to the presentassignee.

The present invention relates to a novel luminaire structure and hasparticular reference to an improved structure of a fluorescent fixturehousing and to devices for connecting together continuous rows ofluminaires.

In the past, many disadvantages have been readily apparent in corridorluminaires of a type similar to that herein disclosed. Some of thesedisadvantages were that the ballast channels were visible and cast darkshadows on the ceilings; the tops of the fixtures were open foradmission of dust and bugs; dark areas were present between fixtureswhen mounted in continuous rows; the ends of the fixtures were dark; thefixtures presented a flimsy appearance and yielded poor lightdistribution; the fixtures required time-consuming methods for mountingthe reflectors in the luminaires; and assembly and mount ing of theluminaire was rendered diflicult by the inclusion of numerous componentswhich are obviated by the present invention.

The present invention is directed to a luminaire that eliminates thesedisadvantages and provides an attractive, simply constructed, andpractically useful apparatus.

An object of the invention, therefore, is the provision of a novel andeflicient luminaire structure.

A further object of the invention is the provision of a novel andeflicient device for joining such luminaires in end-to-end relation.

Another object of this invention is to provide a luminaire constructionwhich minimizes dark areas between adjacent fixtures when mounted incontinuous rows.

A further object is to provide a luminaire construction having meansassociated therewith for emphasizing continuous and uninterruptedribbons of light when mounted in end-to-end relation.

Another object of the invention is the provision of a luminaire having anovel arrangement for furnishing a good brightness distribution allaround the luminaire.

Still another object is to provide a fixture with novel means for hidingthe ballast or wiring from direct View and for reducing or eliminatingceiling dark spots caused thereby.

Another object of the invention is to provide a fixture which is closedin a novel manner to prevent dust and bugs from entering the fixture.

Further objects are to provide a plastic shield which prevents bowinginward or outward, which provides hinging along its entire length, andwhich allows for easy mounting and relamping.

Another object of the invention is to design a fluorescent typeluminaire which has a reflector and a light transmitting shield thataids in directing more light downward.

Still another object of the invention is to provide a Patented Sept. 28,1965 reflector which has a snap-in design, eliminates the need forscrews in mounting, and is shaped to provide the best possiblereflection.

Another object of the invention is to provide a fixture which issuitable both for ceiling mounting and suspension mounting.

Yet another object of the invention is to provide a luminaire with endplates which serve also as lampholder supports and which provide meansfor attaching a novel connector for mounting continuous rows offixtures.

Still another object of the invention is to provide a luminairestructure which has lampholder supports that fold into the channel forshipping or storage and thus provide protection for the lampholder.

On the other hand, an objective of the invention is the provision ofmeans associated with a detachable reflector arrangement for assuringthe retention of a foldable lampholder in its operating position, whendesired.

A further object of this invention is to provide a novel connector usedin conjunction with the adjacent units of low-rnounted luminaires suchas those described in this application, with the connector being of aone-piece design requiring no preassembly in the shop and no screws totighten in the field, that is to say, a connector which simply snapsinto position.

More specifically, it is an object of this invention to provide aconnector which forms tight connections between adjacent luminaires whenmounted and which can be secured simply by twisting the connector endswith a screw driver or similar tool.

Before giving a detailed description of the precise configuration andcooperation of the components of the fluorescent luminaire, a shortenumeration of the major components and the novel method of theirassembly shall be described.

The luminaire structure consists primarily of a channelshaped housinghaving lampholders at each end and having means for holding a reflectorand light-transmitting shield thereto. The housing also serves as ameans to mount the ballast. The luminaire fixture generally is supportedfrom the ceiling either by directly mounting it thereon or by suspendingit therefrom by means of stems attached to the housing. The lampholdersupports, in this arrangement, are hingedly connected to side walls ofthe housing so that they can be collapsed for shipping purposes. Slotsare provided in the lampholder supports for receiving novel connectors,provided by the invention, so that luminaire housings may be joinedend-to-end to form ganged sections of fixture housings. The shield orclosure is so made that its flanges fit over edges of the housing inorder to eliminate any need for the conventional nut-bolt connections orother fasteners. Additionally, the shield is shaped to provide animproved lightdistribution and to conceal ceiling dark spots caused bythe ballast or other opaque components of the luminaire. The presentinvention also provides plastic end covers which can be either lighttransmitting or opaque, or partially opaque and light transmitting sothat the desired degree of light can be obtained at the ends of theluminaire to present a desirable appearance.

These and other objects, features and advantages of the invention willbecome more apparent upon consideration of the following detaileddescription of illustrative embodiments thereof when taken inconjunction with the attached drawings, in which:

FIGS. 1A, 1B, 1C constitute a tripartite side elevational view of aluminaire constructed according to the invention, with parts in sectionand other parts broken away in order to illustrate the invention moreclearly;

FIG. 2 is a transverse sectional view of the luminaire taken alongreference line IIII of FIG. 1A;

FIG. 3 is a perspective view of the luminaire including the lampholdersupports and lampholders;

FIG. 4 is a partial perspective view of an end of the luminaire with thelight-transmitting shield mounted on the housing and with the end coverready to be assembled to the shield;

FIG. 5 is a partial perspective view of the luminaire with a connectorof the invention and reflector shown in a ready-to-be-assembledrelationship and with the lampholder shown in its shipping (dottedlines) and operative positions;

FIG. 6 is a partial perspective view with parts removed and broken awayof two adjacent luminaires mounted end-to-end and secured together bythe connector and with the shield or closure members of one of theluminaires being partially assembled;

FIG. 7 is a perspective view of the central portion of the luminaireshowing one center lampholder support in a shipping position and anothercenter lampholder support in its operative position;

FIG. 8 is a perspective view with parts broken away of the centralportion of a luminaire as shown in FIG. 7, but with the reflectors andshields being assembled;

FIG. 9 is a front elevational view of the connector of the invention;

FIG. 10 is a plan view of the connector of the invention; and

FIG. 11 is a side elevational view of the connector of the invention.

Referring more particularly to FIGS. 1A, 1B, and 1C, it can be seen thatthe luminaire of this invention has a generally rectangular form.Housing 10 is an inverted channel-shaped member from which are suspendedinwardly connected lampholder supports 12 and 14 which in turn supportthe lampholders 70 and the fluorescent lamps 74 as described hereinafterin greater detail.

The lampholder supports 12 are mounted on the opposite ends of theluminaire, as shown in FIGS. 1B and 1C. In the more lengthy luminaires,additional lampholder supports 14 are mounted in a back-to-backrelationship in the middle of the housing 10. The details of thestructure of these elements are described later. Both the housing 10 andthe lampholder supports 12 can be made of any suitable material, such assheet steel. Supported also from this housing 10 is a plastic shield orclosure member 16. This shield 16 is attached to the housing without theuse of screws, bolts, or the like. FIGS. 1A, 1B, and 10 form what isknown in the art as a tandem rapid-start luminaire. The luminaireillustrated by these figures contains two lamps 74 supported in tandemand includes the back-to-back lampholder supports 14 as shown. FIGS. 1Band 1C, the opposite end portions of the luminaire, also illustratedecorative end covers 18, preferably made of a plastic material andwhich are described in more detail later.

The housing 10, as clearly illustrated in FIG. 2, is of a generallyinverted U-shaped configuration having a bight portion 20 and side walls22. Extending along the entire length of the side walls 22 and outwardlytherefrom are flanges 24 which in turn have upwardly directed edges 26extending therefrom, the purpose of which is described below. Thishousing 10 is preferably of a one piece construction, with flanges 24and edges 26 thereof formed by bending the material used to the desiredshape. Fitting in the inverted U-portion of the housing is a ballastassembly 28 which is secured to the bight portion 20 of the housing byany conventional means such as nuts and bolts 30.

The plastic shield 16 is fashioned of any desired lighttransmittingresilient plastic material, such as polystyrene and the like, and isadapted to fit over the upturned edges 26 of the housing 10. Toaccomplish this, the shield 16 has downturned flanges 32 in registrationwith the edges 26 of the housing in the operative position of theshield. These flanges 32 extend from side walls 34 of the shield 16.Connecting these side walls 34 is a concave bight portion 36. This bightportion 36 serves to concentrate the rays 'of light so as to direct morelight downwardly.

The mounting of the shield 16 is clearly shown in FIG. 6. To attach theplastic shield 16, the flange 32 of the far side of the refractor ishooked over the corresponding edge 26 of the housing 10. The shield 16is then swung upward until it covers the inner part of the housing 10completely, and with a slight horizontal push on the free side wall 34toward the far side of the housing the free flange 32 of the plasticshield 16 can be dropped into engagement with the edge 26 on the nearside of the housing 10. This can be accomplished because when the flange32 of the far side is pushed flush against the far side wall 22 of thehousing 10 the spacing is such that the flange 32 on the near side justclears the edge 26 of the housing 10. The above mentioned horizontalpush then engages the free flange 32 over the near edge 26 and moves thefar flange 32 towards the far edge 26. Thus, when in its operativeposition, the flanges 32 are each seated in the space on each side ofthe housing 10 formed by each housing side wall 22 and each edge 26.

The resiliency of the shield 16 will allow for some flexing of the sidewalls 34 if needed to engage or disengage the shield 16 and the housing10, but the present luminaire is so designed that such flexing will notnormally be necessary. For servicing the units, the shield will hangsafely from either side in the relationship illustrated in FIG. 6. Thereflectors 40 of the adjacent luminaires shown in FIG. 6 have beenremoved to more clearly illustrate the remaining parts. However, thereflectors 40 when mounted in this arrangement appear substantially thesame as that shown in FIG. 8, which illustrates adjacent reflectors inthe central portion of longer luminaires.

The outwardly extending flanges 24 of the housing 10 have lanced tabs 38as best shown in FIGS. 2 and 5. A reflector 40 is again generally ofU-shaped configuration and at its upper extremities has outwardlyextending edges 42 which are engaged with the inwardly directed lancedtabs 38 of the housing 10. The reflector 40, in this example, is formedof successive flat portions 44 each bend with respect to the other so asto form the aforementioned U-shaped configuration. The reflector 40 isso shaped as to provide a more eflicient and desirable illuminationeffect and also to make the reflector 40, which is desirably made of aresilient metal, more firmly secured to the housing 10 due to the sidesof the U of the reflector 40 being bent so as to be urged outwardly.

The resiliency of the reflector 40 is shown in FIG. 5 wherein the solidlines of reflector 40 indicate its free position while the dotted linesof reflector 40 indicate a compressed position. Each end of thereflector 40 has a cut-out 45 which fits around the central stem-likeportion 71 (FIGS. 5 and 8) of a lampholder 70 so as to aid inmaintaining the lampholder 70 and lampholder support 12 or 14 in theiroperative positions. The reflector 40 is of a length so as to span thedistance or space between cooperating pairs of lampholders 70 and theirsupports 12 and 14. When tandem pairs of lampholders and their supportsare mounted in a housing, two tandem reflectors are employed, onereflector between each pair of lampholders and supports, respectively.

The reflector 40 fits over and hides the ballast 28 and associatedwiring so as to eliminate any possibility of their casting dark shadowson the ceilings. In addition, the sides 34 of the shield 16 extendalmost to the top of the housing 10 so that any dark areas on theceiling directly above the luminaire are not readily apparent.

The housing serves not only the function of supporting the lampholderssupports 12 and 14, ballast 28, reflector 40, and shield 16, but also asthe means for suspending the luminaire from a ceiling or mounting itdirectly to a ceiling. Square knockouts 46 and 48, as shown in FIG. 3,are a means for rod or stem mounting in the suspension system. The stemsare not shown in the drawings. The two outside holes 48 are for singlestern mounting and the two inside holes 46 are for twin stern mounting.That is, when only a single luminaire is being mounted twin stems, whichconsists of two identical stems, are secured to the center knockouts 46.However, when a plurality of luminaires are mounted end-to-end, twosingle stems are secured to the first luminaire at the knockouts 48 anda single stem is mounted on the subsequent luminaires at the knockout 48furthest from the first luminaire. The end connection between adjacentluminaires provides the support for the end of a luminaire not supportedby a stem. Two long thin rectangular knockouts or slots 50 are providedfor direct ceiling mounting. Bosses 49 space the housing 10 from theceiling when mounted directly thereto. Other knockouts, such as 52 inthe bight portion 20 of the housing 10, are for line leads and the like.

An end portion of the luminaire showing the combination and assembly ofthe reflector 16, lampholder support 12, and end cover 18 with thehousing 10 is shown in FIG. 4. The end cover 18 is provided with hookedfingers 55 which engage the edges of an opening 53 in end wall 59 andwhich seat on shoulders 57, respectively, of the opening 53. Portion 56has been cut-out of the wall just above the shoulder 57. This cut-out 56makes it easier to insert the fingers 55 behind the end wall 59. Theshape of the end cover is made so as to conform to the end wall 59 ofthe shield and to provide a decorative and functional closure therefor.The plastic end cover 18 can be made of a light transmitting or opaqueplastic depending on the results desired. It is more desirable, however,to make the end covers 18 light transmitting for they then willprovidefor illumination of the otherwise dark ends of the fixture. The endcover 18 is provided with a peripheral flange tightly abutting the endwall 59. If desired, the width of the flange can be varied to attain amore luminous appearance, but in any case, the cover will not have anydistinct shadows from the opaque elements in the luminaire. To mount anend cover it is first centered against the unit end and slightly aboveits normal position and then thrust downwardly to slide it into a securattachment with the end wall 59.

The side walls 22 of the housing member 10 are provided with elongatedslots 61 which receive hinging screws 60, as best shown in FIG. 5. Thelampholder supports 12 have flanges or wings 62 by which the hingingscrews connect the lampholder supports to the housing. The lampholdersupports also have inclined flanges or wings 64, so shaped as not tointerfere with the mounting of the reflector 40. Connected to the lowerend of each of the wings 64 is a base portion 66 which has a T-shapedcutout 68 for receiving a lampholder 70. The lampholders 70 are securedto the supports 12 by means of bolts 72 extending through a leg of thecut-out 68 and engaging the lampholder. Fluorescent lamps 74 are, ofcourse, supported by opposing pairs of the lampholders 70. Thelampholder supports 12 are further provided with knockouts 76 in theirend walls 65, which serve to allow wiring 77 to pass through gangedsections of the luminaires.

When received in the shipping carton, the lampholder supports 12 arepivoted about their hinging screws 60 to lie flush against the bightportion 20 of the housing 10. To place a lamp holder support in anoperative position, it must first be rotated from its shipping positionto a vertical position, as shown in FIG. 5. While in the shippingposition the hinging screws 60 need be only loosely connected. Anoverlapping flange 58 (FIG. 4) extends from the top edge of eachlampholder support 12 and 6 rests over the bight portion 20 of thehousing 10 when a lampholder support 12 is in the operative position.When rotated to its vertical position, the lampholder support 12, isthen slid centerward as far as possible, by means of the hinging screws60 sliding in the elongated slots 61, the hinging screws are thentightened so that the flange 58 engages the end of the housing 10 asnoted above.

For continuous rows of fixtures, the end of a lampholder support 12 ofone luminaire is placed adjacent to a lampholder support 12 of another.A connector 80, which will be described in more detail later, is thenslipped into engagement with the lampholder supports so that connectortabs 82 extend outwardly through the end of one lampholder support bymeans of elongated rectangular slots or apertures 78. When the tabs 82of the connector are inserted in the slots, a flange 84 of the connectorsnaps into position over the outside of the base 66 of the lampholdersupport by means of dimples 86, which engage apertures 87 in base 66 andprovides for a snug friction fit. The first unit A should be installedwith the connector tabs 86 pointed in a longitudinal direction as seenin FIG. 6. A succeeding unit B is then raised into its position andmounted with the ends of adjacent units about it, and the connector tabs82 in the slots 78. With a turn of a screw driver or the like, the tabs82 are bent and the units locked together. Accordingly, when a number ofluminaires are mounted in tandem in end-to-end abutting relation, thearray of luminaires presents the appearance of a continuous ribbon oflight extending longitudinally along the total length thereof.

In certain luminaires, employing a single lamp 74, there are only twolampholder supports 12. But, in longer luminaires there are, forexample, center lampholder supports 14 as illustrated in FIGS. 1A andFIG. 7. It will be appreciated, however, that lamps may also be mountedin parallel, employing appropriate lampholders of course in both theshorter and longer luminaires. FIG. 7 shows two center lampholdersupports 14, one in a shipping position and another in an installedposition. While being shipped, the center lampholder support 14 likewiseare pivoted upon the hinged screw connection 92 so that they remainflush with the bight portion 20 of the housing member. When swung downto a vertical, or installed position, they are prevented from furtherrotation by means of detents 94 on the sides of the U-shaped bracketportion of the lampholder support 14 which engage apertures 93 orsimilar indent means the side walls 22 of the housing member.

The central lampholder supports 14 are generally simi lar to thelampholder supports 12 employed at the ends of the luminaires, with likeportions having like reference numerals. The central lampholder supportshave eliminated the end wall 65 found in the end lampholder supports 12and have substituteda return flange 96 which serves as a brace and guidefor the inserted lampholders 70.

In the longer luminaires two of the shields 16 employed in the shorterluminaires are required since the longer ones are generally just twicethe size of the shorter luminaires. The two shields are placedend-to-end (FIG. 8) and meet where the backs of the center lampholdersupports 14 abut one another. This is where light leakage, if any, wouldbe at a minimum because no part of the lamps 74 is in this immediatearea, the ends of the lamps 74 leaving a blank area.

FIGS. 9, 10 and 11 illustrate the details of the connector 80 of thisinvention. FIG. 10 shows the connector 80 to be of generally U-shapedconfiguration with the bottom flange 84 co-extending with bight portionto side members or walls 88 of the connector. The bottom flange 84 isinclined at an angle to the lower edges 91 of the side walls 80 to givea pinching fit and has two dimples or detents 86 which serve to lock theconnect-or 80 to the apertures 87 of the corresponding lampholdersupport 12, as explained earlier, and as illustrated in FIGS. and 9. Thebight portion 90 of the connector is cut out at 98 so as to facilitateaccess to the lampholder 70 and provide space for the necessary wiring77 again as seen in FIG. 9. The legs or side walls 88 of the connector80 form tabs 82 which serve as the locking portions of the connector 80.The side walls 88 are also notched so as to have shoulders 100 which actas stops to limit the insertion of the side walls into the slots 78 ofthe lampholder supports. The bight portion 90 of connector 80 will abutagainst the edge 65 of lampholder support 12 if the connector is notprovided with shoulders 100, so as to limit movement of the tabs 82 ofthe connector 80 into the slots 78. This connector 80 is made ofbendable metal so that the tabs can be bent with ease by a screw driveror the like. However, the connector is strong enough to hold theend-to-end mounted luminaires in a stable, operating position. Thus,there is illustrated a snap-on connector which is of a one-piece designrequiring no preassembly in the shop and no screws to tighten in thefield since the connector simply snaps into position.

This invention therefore, provides for a corridor type or similarelongated fixture which is inexpensive to produce and which provides anup-to-date appearance and which eliminates many of the disadvantagescommon up to this time. The reflector and luminous ends serve as an allenclosed, extended lighting fixture which minimizes dark areas betweenadjacent luminaires in continuous rows give an uninterrupted ribbon oflight in a much stronger construction than that used previously. Sincethe shield extends up to the ceiling it provides a good brightnessdistribution all around the luminaires and hides the ballast channelfrom direct view. Because of the way the plastic shield is supported bythe housing, there not only is provided a device which allows for easymounting and relamping, but one that prevents dust and bugs fromentering the fixture and prevents the plastic from bowing inward oroutward.

Since it is obvious that the invention can be embodied in other formsand constructions within the spirit and scope of the invention, as wouldbe apparent to one skilled in the art, it is to be understood that theparticular form shown is but one of such embodiments and with variousmodifications and changes being possible, the invention is not limitedin any way with respect thereto. Moreover, it is to be understood thatcertain features of the invention can be employed without acorresponding use of other features thereof.

We claim as our invention:

1. In a luminaire, the combination comprising an elongated housing withan open bottom, lampholder supports mounted adjacent opposite ends ofthe housing, reflector means secured to said housing and covering theopen bottom thereof so as to enclose a ballast and wiring space betweenthe reflector and housing, a generally U-shaped light-transmittingshield hingedly and releasably mounted on said housing, said shieldhaving light-transmitting end walls integral therewith, said end wallshaving a cut-out portion, the edges of said cut-out portion definingopposing aligned stepped upper and lower shoulders, at least one endcover engaging one of said end walls, said end cover having hook means,said hook means being of sufficient dimension to be insertable withinsaid cut-out portion above said upper shoulder and engageable with saidend wall when resting on said lower shoulder.

2. In a luminaire, the combination comprising an elongated invertedchannel-shaped housing, outwardly and upwardly directed flangesextending from opposite side walls of said housing, a reflectorextending the length of said housing secured to and generallycoextensive with the outer periphery of said flanges to cover the openbottom of said housing, means carried by said housing for supporting atleast one light source, a generally U-shaped light-transmitting shieldenclosing at least the major part of said housing, said shield havingopposed portions at the free ends thereof directed inwardly toward eachother a substantial distance, means on the terminal ends of saidinwardly directed shield portions releasably engaging the upwardlydirected flanges of said housing, said means abutting against saidoutwardly directed housing flange and resting thereon, whereby a pivotalrelationship exists between one of said housing flanges and itscorresponding shield means when the other shield means is detached fromits corresponding housing flange, whereby said inwardly directed shieldportions provide for upwardly directed light therethrough and preventthe casting of objectionable shadows on the mounting surface, saidshield having light-transmitting end walls integral therewith, said endwalls having a cut out portion, the edges of said out out portiondefining opposing aligned stepped upper and lower shoulders, at leastone end cover engaging one of said end walls, said end cover having hookmeans, said hook means being of sufficient dimension to be insertablewithin said cut out portion above said upper shoulder and engageablewith said end wall when resting on said lower shoulder.

3. In a luminaire, the combination comprising an elongated housinghaving an open bottom, lampholder supports mounted adjacent oppositeends of said housing, reflector means secured to said housing andcovering the open bottom thereof, a generally U-shapedlight-transmitting shield hingedly and releasably mounted on saidhousing, said shield having light-transmitting end walls integraltherewith, said end walls having a cut away portion exposing the end ofsaid housing and said lampholder support, the edges of said cut awayportion defining opposing aligned stepped upper and lower shoulders, atleast one end cover engaging one of said end walls to enclose said cutaway portion, said end cover having hook means, said hook means being ofsufiicient dimension to be insertable within said cut out portion abovesaid upper shoulder and engageable with said end wall when resting onsaid lower shoulder, whereby said end cover conceals the opaque elementsat the end of said housing.

4. In a luminaire, the combination comprising an elongated housing withan open bottom, lampholder supports mounted adjacent opposite ends ofthe housing, reflector means secured to said housing and "covering theopen bottom thereof so as to enclose a ballast and wiring space betweenthe reflector and housing, a generally U-shaped light-transmittingshield hingedly and releasably mounted on said housing, said shieldhaving light-transmitting end walls integral therewith, said end wallshaving a portion cut away to conform generally to the contour of thecrosssection of the edge of said cut away portion defining the opaqueelements in said luminaire, opposing aligned stepped upper and lowershoulders, at least one end cover engaging one of said end walls, saidend cover being large enough to cover said cut away portion but smallerthan said end wall, said end cover having hook means, said hook meansbeing of suflicient dimension to be insertable within said cut awayportion above said upper shoulder and engageable with said end wall whenresting on said lower shoulder.

5. In a luminaire, the combination comprising an elongated housing withan open bottom, lampholder supports mounted adjacent opposite ends ofthe housing, reflector means secured to said housing and covering theopen bottom thereof so as to enclose a ballast and wiring space betweenthe reflector and housing, a generally U-shaped light-transmittingshield hingedly and releasably mounted on said housing, said shieldhaving light-transmitting end walls integral therewith, said end wallshaving a cut out portion, the edges of said cut out portion definingopposing aligned stepped upper and lower shoulders, at least onelight-transmitting end cover engaging one of said end walls, said endcover having hook means, said hook means being of sufficient dimensionto be insertable within said cut out portion above said upper shoulderand engageable with said end wall when resting on said lower shoulder,said end cover having a peripheral flange portion abutting said end wallto provide spacing therefrom, whereby said light-transmitting end coverpresents a luminous appear- 2,694,775 11/54 FIOI'GIIE? 240-5111 anceduring operation of said luminaire. 2,913,575 11/59 Lipscomb 240106 XReferences Cited by the Examiner 2,993,115 7/61 Rosenblatt 24051.11

UNITED STATES PATENTS 5 EVON C. BLUNK, Examiner. 2,291,488 7/42'Naysmith NORTON ANSHER, Primary Examiner.

2,531,232 11/50 Naysmith 24051.11

1. IN A LUMINAIRE, THE COMBINATION COMPRISING AN ELONGATED HOUSING WITHAN OPEN BOTTOM, LAMPHOLDER SUPPORTS MOUNTED ADJACENT OPPOSITE ENDS OFTHE HOUSING, REFLECTOR MEANS SECURED TO SAID HOUSING AND COVERING THEOPEN BOTTOM THEREOF SO AS TO ENCLOSE A BALLAST AND WIRING SPACE BETWEENTHE REFLECTOR AND HOUSING, A GENERALLY U-SHAPED LIGHT-TRANSMITTINGSHIELD HINGEDLY AND RELEASABLY MOUNTED ON SAID HOUSING, SAID SHIELDHAVING LIGHT-TRANSMITTING END WALLS INTEGRAL THEREWITH, SAID END WALLSHAVING A CUT-OUT PORTION, THE EDGES OF SAID CUT-OUT PORTION DEFININGOPPOSING ALIGNED STEPPED UPPER AND LOWER SHOULDERS, AT LEAST ONE ENDCOVER ENGAGING ONE OF SAID END WALLS, SAID END COVER HAVING HOOK MEANS,SAID HOOK MEANS BEING OF SUFFICIENT DIMENSION TO BE INSERTABLE WITHINSAID CUT-OUT PORTION ABOVE SAID UPPER SHOULDER AND ENGAGEABLE WITH SAIDEND WALL WHEN RESTING ON SAID LOWER SHOULDER.